So in this equation, I can easily see how each answer is multiplied by -4. 11 x -4 = -44. -44 x -4 = 176. 176 x -4 = -704. and the forth term is -704 x -4 which is 2816.
Answer:
It would take 75.8 minutes for the element to decay to 2 grams.
Step-by-step explanation:
The number of grams of element x, after t minutes, is given by the following equation:

In which X(0) is the initial amount and r is the decay rate.
There are 160 grams of Element X
This means that X(0) = 160.
So


Half life of 12 minutes.
This means that X(12) = 0.5*X(0) = 0.5*160 = 80. So



![\sqrt[12]{(1 - r)^{12}} = \sqrt[12]{0.5}](https://tex.z-dn.net/?f=%5Csqrt%5B12%5D%7B%281%20-%20r%29%5E%7B12%7D%7D%20%3D%20%5Csqrt%5B12%5D%7B0.5%7D)

So


How long would it take for the element to decay to 2 grams?
This is t for which X(t) = 2. So







It would take 75.8 minutes for the element to decay to 2 grams.
Wish I could help. If you give me the real problem I will help you.